Matplotlib tutorial 03



In [1]:

    
# import
import numpy as np
import matplotlib.pyplot as plt

%matplotlib inline



In [2]:

    
# generating some data points
X = np.linspace(-np.pi, np.pi, 20, endpoint=True)
C, S = np.cos(X), np.sin(X)



In [3]:

    
# Simply plotting these in same plot

plt.plot(X, C,
         X, S)









    Out[3]:





[<matplotlib.lines.Line2D at 0x78312e8>,
 <matplotlib.lines.Line2D at 0x7831cf8>]

Adding a Legends



In [6]:

    
plt.plot(X, C, label='Cos')
plt.plot(X, S, label='Sin')

plt.legend(loc='upper right')









    Out[6]:





<matplotlib.legend.Legend at 0x7d11c88>



In [7]:

    
plt.plot(X, C, label='Cos')
plt.plot(X, S, label='Sin')

plt.legend(loc='best')  # python itself choose the best location for legends









    Out[7]:





<matplotlib.legend.Legend at 0x7d85630>



In [9]:

    
# one more way to add legends

l1, = plt.plot(X, C)
l2, = plt.plot(X, S)

plt.legend([l1, l2],loc='best')  # this will print the legends generated by matplotlib









    Out[9]:





<matplotlib.legend.Legend at 0x7e64f28>



In [10]:

    
# let's modify the matplotlib generated labels

l1, = plt.plot(X, C)
l2, = plt.plot(X, S)

plt.legend([l1, l2],["Cos Wave", "Sin Wave"], loc='best')  # python itself choose the best location for legends









    Out[10]:





<matplotlib.legend.Legend at 0x7ed4dd8>



In [21]:

    
# What if we are plotting multiple charts in single plot

l1,l2, = plt.plot(X, C, X, S)
print(l1, l2)
plt.legend([l1, l2],["Cos Wave", "Sin Wave"], loc='best')  # python itself choose the best location for legends









    



Line2D(_line0) Line2D(_line1)






    Out[21]:





<matplotlib.legend.Legend at 0x902eeb8>

Adding Grid & Margins



In [28]:

    
l1,l2, = plt.plot(X, C, X, S)
plt.legend([l1, l2],["Cos Wave", "Sin Wave"], loc='best')

# adding Grid & Margins
plt.grid(True)
plt.margins(0.2)  # 20%

Modifying axis limits



In [30]:

    
l1,l2, = plt.plot(X, C, X, S)
plt.legend([l1, l2],["Cos Wave", "Sin Wave"], loc='best')

# adding Grid & Margins
plt.grid(True)
plt.margins(0.2)  # 20%

# printing current limits
print("Current Limits")
print(plt.xlim())
print(plt.ylim())









    



Current Limits
(-4.3982297150257104, 4.3982297150257104)
(-1.399316898601334, 1.3959013916080039)

Changing Limits



In [40]:

    
l1,l2, = plt.plot(X, C, X, S)
plt.legend([l1, l2],["Cos Wave", "Sin Wave"], loc='best')

# adding Grid & Margins
plt.grid(True)
plt.margins(0.2)  # 20%

# printing current limits
print("Current Limits")
print(plt.xlim())
print(plt.ylim())

# modifyint limits
plt.xlim([-6, 6])
plt.ylim([-1.5, 1.5])









    



Current Limits
(-4.3982297150257104, 4.3982297150257104)
(-1.399316898601334, 1.3959013916080039)






    Out[40]:





(-1.5, 1.5)

Changing Plot Size



In [41]:

    
plt.figure(figsize=(8,6))

l1,l2, = plt.plot(X, C, X, S)
plt.legend([l1, l2],["Cos Wave", "Sin Wave"], loc='best')

# adding Grid & Margins
plt.grid(True)
plt.margins(0.2)  # 20%



In [ ]: